We studied the role of peripheral and central catecholamines and angiotensin II in the regulation of cardiovascular function. We established that specific brain areas containing adrenaline neurons control both catecholamine and vasopressin release and influence blood pressure and heart rate. We determined the precise source of intermediate and posterior lobe pituitary catecholamines. There are close interactions between beta-adrenergic receptors and arterial angiotensin-converting enzyme. The brain angiotensin system, both at the converting enzyme and at the receptor levels, is involved in cardiovascular control in the spontaneously hypertensive rat.